Retaliatory attacks by Egypt’s military in Sinai have tended to hit militant-sympathetic neighborhoods and just kill everybody in the area wholesale, though official statements always label all the slain militants or at least suspects, whether they were obvious civilian bystanders or not.

The timing and location of the attack suggest it’s a faction that doesn’t like Hamas, however, as Egypt has just recently opened relations with Hamas, and reopened the Gaza border crossing. Since the 2013 coup, the junta has tended to blame Hamas for militant attacks if they can’t definitively pin them on ISIS, and whoever these “masked militants” are may be counting on that to derail the rapprochement.